[A] Tokyo Electric Power Co. (TEPCO) project to freeze radioactive water to prevent it from further contaminating surrounding areas and the Pacific Ocean has hit a major snag: the water won’t freeze.

In March 2011, a massive earthquake and tsunami triggered multiple meltdowns at the Fukushima Daiichi nuclear plant. One of the major obstacles to decommissioning the failed reactors and removing their spent fuel rods is the large quantities of radioactive water that have been accumulating at and beneath the plant. This water not only poses a safety threat to workers on site, but has also been leaching into groundwater and flowing into the ocean.

Not freezing, and behind schedule

Recently, TEPCO launched two related programs to contain existing contamination and limit the flow of new water into the contaminated area. Both consist of digging trenches for pipes, then filling the pipes with an aqueous solution of calcium chloride cooled to -30°C (-22°F). The goal of the first, smaller project is to freeze 11,000 metric tons of radioactive water that has pooled beneath two of the failed reactors.

This project is widely seen as a pilot project for the much larger, more ambitious plan to use pipes to actually freeze the soil and create a 1.4 km (0.9 mile) “ice wall” to prevent more groundwater from infiltrating down into the underground reactors and becoming radioactive.

But on June 17, TEPCO announced that even the smaller project was having difficulties.

“We have yet to form an ice plug because we can’t get the temperature low enough to freeze the water,” a company spokesperson said.

The company also said that fluctuating water levels were making it difficult for the water to actually freeze.

“We are behind schedule, but have already taken additional measures, including putting in more pipes, so that we can remove contaminated water from the trench starting next month,” the spokesperson said.

Cleanup plagued with gaffes and errors

The recent setback added weight to criticisms of the larger ice wall plan by scientists, environmentalists and politicians. Although the ground-freezing technique has been successfully used before in the construction of tunnels near waterways, critics have noted that the technology has never been tested on a geographic or time scale as large as that needed for TEPCO’s plans.

Meanwhile, TEPCO continues with other plans designed to slow the buildup of radioactive water. The company has been pumping radioactive water out of the basements of the reactors and into giant temporary containment tanks. It has also been dumping both radioactive and non-radioactive water into the Pacific Ocean – the former pumped out of the basements, and the latter out of the ground upslope from the nuclear plants, to prevent it from reaching the reactors and becoming contaminated.

Even with all of these measures, an estimated 300 tons of water still flow into the plant and become radioactive every single day.

A complete decommissioning of the failed plant is expected to take decades, and experts have warned that some previously residential areas may have to be permanently abandoned due to persistent radioactive contamination.

Recently, Japanese environment minister Nobuteru Ishihara came under public fire after making comments that critics interpreted as downplaying the plight of people who are still unable to return their homes. The minister had suggested that most people would be willing to accept permanent storage of radioactive waste in their communities, as long as the government paid them enough money.

“It was extremely regrettable,” Fukushima Governor Yuhei Sato said. “The remarks rode roughshod over the feelings of residents who are longing for their hometowns.”